1. Field of the Invention
This invention relates generally to building blocks, and more particularly, to an improved apparatus for enhancing the faces of such blocks to improve their appearance.
2. Description of the Related Art
Building blocks are often made by mixing sand, gravel, cement and water, pouring the mixture into a mold and applying vibration and pressure. The blocks formed are then dried. These blocks, known sometimes as cinder blocks, are commonly used to build walls and building structures.
Efforts have been made to enhance the bland, dull appearance of these blocks. These efforts include roughening the faces or applying a texture during the molding step. Efforts have also been made to grind away a layer, about 1/16 of an inch to give the blocks more of the appearance of granite or marble. One such device described in U.S. Pat. No. 5,085,008 employs a rotating drum to which is adhered an abrasive for grinding the block as it passes beneath the drum; an alternative device had the block pass between parallel saw blades. The drum produces an enhanced building block face or faces, however, the device also gouges or tears at the face which tends to remove an excessive amount of the small rocks embedded in the cement of the block. This detracts from the appearance of the face and also provides numerous small recesses into which mortar may enter during the process of constructing a wall. This mortar is very difficult and time consuming to remove. The presence of mortar on the facing surface of a block further detracts from its aesthetic value by causing discolorations. The rough surfaces also tend not to reflect much light and so appear dull and lifeless.
Another device that may be used for enhancing the faces of cinder blocks is one that includes a rotating belt sander for smoothing the surfaces of the block. At least two problems exist with such a system. First, a belt sander tends to break down too rapidly causing a wide variance in the quality of the enhanced blocks and making it uneconomic. Another major problem is that the sanding operation is dry, and thus, large quantities of dust are released into the air. In many locations, allowing the dust to escape into the atmosphere is illegal. Hence, expensive dust capturing systems are required.